Answer to Question #55447 in Statistics and Probability for josh

Question

a company that manufactures rivets believes the shear strength of the rivets they manufacture follows a normal model with a mean breaking strength of 950 pounds and a standard deviation of 40 pounds

a) what percentage of rivets selected at random will break when tested under a 900 pound load?
b) you're trying to improve the rivets and want to examine some that fail. use a simulation to estimate how many rivets you might need to test in order to find three that fail at 900 pounds or below.